A new inquiry into the 2010 presidential plane crash near Smolensk, Russia was launched by a “mythomaniac” Polish minister just to undermine President of the European Commission Donald Tusk, a former defense minister said in an interview.

The inquiry, backed by the right-wing Law and Justice Party (PiS) of Lech Kaczynski’s twin brother Jaroslaw, has nothing to do with fact-finding, the ex-minister believes. Instead, it is to seek revenge against PiS’ political opponents like Tusk.

“It is very bad for PiS, given the way Macierewicz addresses the issue,” Siemoniak said, as quoted by Polish media.

On Wednesday, Poland’s defense minister Antoni Macierewicz said to the national parliament that a new investigation of the 2010 plane crash near Smolensk was “to reveal hidden or unknown information” related to the Smolensk tragedy, according to the Dziennik newspaper. He pointed out that some senior officials would be held accountable for their “negligence” during the organization of the presidential flight.

In February this year, Macierewicz announced that Poland was reopening the investigation due to “mistakes” made in the previous one.

Previously in March, Macierewicz slid into conspiracy theories and claimed the Smolensk tragedy was “an act of terrorism” and Russia had been “profiting” from it. Last November, the PiS government shut down a website with a comprehensive collection of documents relating to the crash and threatened to prosecute Tusk, Prime Minister at the time of the tragedy, for alleged negligence in investigating the incident.

In 2010, relations between the-then President Lech Kaczynski, the twin brother of Jaroslaw, who still leads right-wing conservative PiS, and Tusk's center-right government were strained. Two years after the Smolensk crash, Jaroslaw Kaczynski said that Tusk bears the utmost responsibility for the disaster.

Five top officials, including Tusk’s staff, under trial for “negligence”

Earlier on Thursday, five former Polish officials appeared in court to face charges for “negligence” during the preparation of the presidential flight on April 10, 2010.

Most senior among them is Tomasz Arabski, former head of PM Tusk’s chancellery, followed by two officials, named Monika B. and Mirosław K., who worked at Prime Minister’s office at that time. They are followed by two further employees of the Polish embassy in Moscow, Justyna G. and Grzegorz C.

The charge alleges that Arabski failed to report that the military airfield in Smolensk, where the crash happened, was not on the list of international airports suitable for the VIP plane to land at, according to Radio Poland. Arabski had denied the allegations saying that he helped organize Tusk’s flight to Smolensk three days prior to the crash, but had not been in charge of the presidential flight.

On April 10, 2010, a Tu-154 VIP aircraft of the Polish Air Force crashed on final approach at Smolensk airport, all 96 on board, including the-then president Kaczynski, his wife as well as top military and government officials.

An investigation by Russia’s Interstate Aviation Committee – the main fact-finding body in charge of air incidents – found that pilots had ignored repeated warnings by Smolensk air traffic controllers (ATC) who urged the VIP flight to go around because of bad weather. The cockpit voice recorder (CVR) data also found out was the crew were under extreme stress as commandant of the Air Force pressed the captain to continue descent against the ATC’s warnings.